Charge-based capacitive sensor array for CMOS-based laboratory-on-chip applications

In this paper, we present a capacitive sensor array for highly integrated lab-on-chip (LoC) applications using the charge-based capacitance measurement method (CBCM). The core-CBCM sensor chip is designed and implemented in 0.18 micron CMOS process featuring an array of capacitive sensors; an offset cancellation module and a low complexity analog-to-digital converter (ADC). This sensor chip is incorporated with a microfluidic channel using direct-write fabrication process. We demonstrate the testing results using chemical solvents with known dielectric constants in order to show the viability of the proposed sensor chip for LoCs.